From 687c4c9d7f1a246ed30c5d2bbd226624259def0b Mon Sep 17 00:00:00 2001
From: Michael Bull <mikebull94@gmail.com>
Date: Wed, 24 Jan 2018 12:58:26 +0000
Subject: [PATCH] Omit "this" prefix from method references

https://kotlinlang.org/docs/reference/whatsnew12.html#support-for--foo-as-a-shorthand-for-thisfoo
---
 README.md                                     |  2 +-
 .../result/example/service/CustomerService.kt | 23 +++++++++++++------
 2 files changed, 17 insertions(+), 8 deletions(-)

diff --git a/README.md b/README.md
index 3bf1813..8387575 100644
--- a/README.md
+++ b/README.md
@@ -83,7 +83,7 @@ having sufficient privileges,  and the command executing the associated action.
 
 ```kotlin
 tokenize(command.toLowerCase())
-    .andThen(this::findCommand)
+    .andThen(::findCommand)
     .andThen { cmd -> checkPrivileges(loggedInUser, cmd) }
     .andThen { execute(user = loggedInUser, command = cmd, timestamp = LocalDateTime.now()) }
     .mapBoth(
diff --git a/example/src/main/kotlin/com/github/michaelbull/result/example/service/CustomerService.kt b/example/src/main/kotlin/com/github/michaelbull/result/example/service/CustomerService.kt
index 2412da4..55d1c43 100644
--- a/example/src/main/kotlin/com/github/michaelbull/result/example/service/CustomerService.kt
+++ b/example/src/main/kotlin/com/github/michaelbull/result/example/service/CustomerService.kt
@@ -1,10 +1,16 @@
 package com.github.michaelbull.result.example.service
 
-import com.github.michaelbull.result.*
+import com.github.michaelbull.result.Err
+import com.github.michaelbull.result.Ok
+import com.github.michaelbull.result.Result
+import com.github.michaelbull.result.andThen
 import com.github.michaelbull.result.example.model.domain.Customer
 import com.github.michaelbull.result.example.model.domain.CustomerId
 import com.github.michaelbull.result.example.model.domain.DomainMessage
 import com.github.michaelbull.result.example.model.entity.CustomerEntity
+import com.github.michaelbull.result.map
+import com.github.michaelbull.result.mapBoth
+import com.github.michaelbull.result.mapError
 import java.sql.SQLTimeoutException
 
 object CustomerService {
@@ -12,7 +18,7 @@ object CustomerService {
 
     fun getAll(): Result<Collection<Customer>, DomainMessage> {
         return Result.of(repository::findAll)
-            .mapError(this::exceptionToDomainMessage)
+            .mapError(::exceptionToDomainMessage)
             .andThen { result: Collection<CustomerEntity> ->
                 Ok(result.map {
                     val customer = Customer.from(it)
@@ -39,21 +45,24 @@ object CustomerService {
     private fun updateCustomer(entity: CustomerEntity, old: Customer, new: Customer) =
         Result.of { repository.update(entity) }
             .map { differenceBetween(old, new) }
-            .mapError(this::exceptionToDomainMessage)
+            .mapError(::exceptionToDomainMessage)
 
     private fun createCustomer(entity: CustomerEntity) =
         Result.of { repository.insert(entity) }
-            .mapError(this::exceptionToDomainMessage)
             .map { DomainMessage.CustomerCreated }
+            .mapError(::exceptionToDomainMessage)
 
     private fun findCustomer(customers: Collection<Customer>, id: CustomerId): Result<Customer, DomainMessage.CustomerNotFound> {
         val customer = customers.find { it.id == id }
         return if (customer != null) Ok(customer) else Err(DomainMessage.CustomerNotFound)
     }
 
-    private fun differenceBetween(old: Customer, new: Customer) = when {
-        new.email != old.email -> DomainMessage.EmailAddressChanged(old.email.address, new.email.address)
-        else -> null
+    private fun differenceBetween(old: Customer, new: Customer): DomainMessage.EmailAddressChanged? {
+        return if (new.email != old.email) {
+            DomainMessage.EmailAddressChanged(old.email.address, new.email.address)
+        } else {
+            null
+        }
     }
 
     private fun exceptionToDomainMessage(t: Throwable) = when (t) {